1. Field of the Invention
The invention concerns a fault display device for gyroscopic instruments.
2. The Prior Art
There are known, from French patents 69.41186 and 2,135,861 in the name of the applicant, devices for showing the rotation speed of a gyroscope and of displaying it visually to an observer by means of a colored flap moved by a sensitive moving coil meter.
Such devices may be used in conjunction with other colored flaps indicating the presence or absence of a supply voltage at the terminals of the gyroscope or at an input point to a unit incorporating said gyroscope.
Advantages resulting from such association are described in the previously mentioned patent 2,135,861. However, implementing solutions of this type encounters problems with accommodating the control members, the amount of space swept out by their display devices generally being ill matched to the lack of space available within the indicators that incorporate them; these installation problems may be such, in the case of small indicators, that it proves impossible to integrate the speed indicator device, so rendering unavailable information of extreme utility in so-called "emergency" situations.
A usual type gyroscopic horizon indicator comprises an angle of pitch indicator drum 1, a representation 2 of the aircraft and a fixed roll indication dial 3 with conventional graduation markings relative to which moves a roll pointer 4. Note that the fixed and moving roll indicators may be interchanged, as is sometimes necessary, or moved to the bottom of the instrument (see FIG. 1 in the appended drawings).
In a conventional solution to the alarm indication problem the arrangement as described above is disrupted by the provision, in the pilot's field of view and by means of electro-mechanical devices, of one or two brightly colored (red, for example) flaps.
As has previously been said, it is often difficult to incorporate these solutions and sometimes impossible in the case of the second flap, because of the constraints with regard to available space that these electromechanical devices entail.
Also, and still because of mechanical constraints, the area on the display where these flaps may be caused to appear is not always the optimum one, that is as near as possible the indication concerned.